JP2008512559A - High temperature nanocomposite resin - Google Patents

Abstract

A method of using olefin-containing nanostructured chemicals and silanol-containing nanostructured chemicals as high temperature resins is described. Vinyl-containing nanostructured chemicals are particularly effective for thermosetting resins because they control the movement of polymer chains and segments at the molecular level. Silanol-containing nanostructured chemicals are particularly effective for thermosetting resins containing polar groups. Nanostructured chemicals can be easily incorporated into polymers by direct mixing and polymerization for compatibility with fluoropolymers. Incorporation of nanostructured chemicals into polymers has a positive impact on the physical properties of the polymer. Properties that are most advantageously improved are thermal strain and combustion properties, permeability, optical properties, texture, feel and durability. Other properties include time-dependent mechanical and thermal properties such as creep, compressive residual strain, shrinkage, modulus and hardness. In addition, other physical properties, including low thermal conductivity and gas oxygen permeability are improved. These properties are useful for many applications.

Description

This application claims the benefit of US Provisional Patent Application No. 60 / 608,582, filed Sep. 10, 2004.

The present invention relates generally to high temperature thermoset polymer and fiber reinforced composite methods and compositions. More particularly, the present invention incorporates and uses nanostructured chemicals to control the cure chemistry of the polymer and further affect the thermal, mechanical, and related physical properties of the thermoset polymer. Related to the method.

  The invention also relates to processing and application to nanoscale controlled thermoset polymer composites, coatings, adhesives, seals and molded products. Resin and composite applications include improved composite resins, foams, fibers, paints, coatings, adhesives, and fire printability, surface properties that provide biocompatibility, and permeability control, optical properties and architecture Includes coating.

BACKGROUND OF THE INVENTION It has long been recognized that polymer properties can be highly tuned by variables such as polymer alignment, structure, incorporation of additives and fillers, composition, morphology, thermodynamic and kinetic processing control. Similarly, blends and particles of various sizes and shapes (eg, Teflon, calcium carbonate, silica, carbon black, etc.) can be incorporated into a preform polymer (prepolymer) or mixture of monomers, resulting in a formulation It is known that the physical and material properties of objects can be enhanced. The prior art in thermosetting polymers has also focused on adjusting properties by forming interpenetrating networks and crosslinks that partially or completely occur between chains.

  In the prior art, the desired effect was to reduce the movement of the polymer chains and segments relative to each other. The combination of chain motion reduction combined with a more rigid and thermally stable component ultimately enhances physical properties such as dimensional stability, strength and thermal stability. Unfortunately, all the prior art has the disadvantage that the process is complicated and the length scale cannot be controlled at the 1-50 nm level in all three dimensions. A length scale of 1-50 nm is important for polymer materials. This is because typical polymer chains or crosslinks have a 8 nm reptation diameter and a 50 nm turning radius. The present invention utilizes nanostructured chemicals to achieve process simplification, control of cure chemistry and cure rate, and nanoscale reinforcement of polymer chains to the 1 nm level.

  Furthermore, it has been calculated that since the reinforcement size is reduced to less than 50 nm, they are more resistant to sedimentation and become more effective in providing reinforcement to the polymer system. However, the full application of this theoretical knowledge is not a practical source of particle reinforcement with geometrically well-defined, monodisperse, diameters below the 10 nm range, especially in the range of 1 nm to 5 nm. Has been hindered by

  Prior art associated with thermosetting polymers, interpenetrating networks, polymer morphology, and filler technology has not been able to adequately control the motion and structure of polymer chains, coils and segments at the 1-10 nm level. Furthermore, traditionally, incompatibility of chemical potential (eg, solubility, miscibility, etc.) between polymers and inorganic fillers and chemicals has resulted in a high degree of inhomogeneity in the blended polymer, which is mixed with water It is similar to oil. Thus, there is a need for appropriately sized chemical reinforcements with controlled diameter (nano dimensions), distribution and tunable chemical functionality to further improve the properties of the polymer.

  Recent developments in nanoscience include its exact chemical formula, hybrid (inorganic-organic) chemical composition, larger physical size relative to the size of conventional chemical molecules (0.3-0.5 nm), and larger sizes The small physical size relative to conventional fillers (> 50 nm) allows the ability to cost-effectively produce commercial quantities of materials best described as nanostructured chemicals.

SUMMARY OF THE INVENTION The present invention describes a method for producing improved high temperature polymer thermosetting resins and composites by controlling curing chemistry, structure and properties at the nanoscale length scale. The resulting nanopolymers themselves or in combination with other polymers or other macroscopic reinforcements such as foams, screens, meshes, fibers, clays, glass minerals and other fillers and other chemicals including catalysts In combination with, it is completely useful. Nanoalloyed polymers are particularly useful for producing polymer compositions having desirable physical properties such as adhesion to fiber reinforcement and metal surfaces, water repellency, low melt viscosity, fire resistance and oxidation resistance.

  Preferred compositions presented herein comprise a combination of two major materials. (1) A cage or partial cage (FIG. 1) having a vinyl or other olefinic R group on the POSS cage and (2) a silanol group. These material combinations include nanostructured oligomers, or nanostructured polymers, polyhedral oligomeric silsesquioxanes, polysilsesquioxanes, polyhedral oligomeric silicates, polysilicates, polyoxometalates, carboranes, boranes and many It is utilized as a chemical crosslinker or curing accelerator in the form of carbon in the form or having nanoscale dimensions. Crosslinkers are then utilized with hydrocarbonenes, or silanes and silicones, or phosphines, or thiols or sulfur and copolymers, phenols, novalacs, resoles, epoxies, cyanate esters, urethanes, polyimides, bismaleimides, and combinations thereof. The

  Preferably, the method of incorporating the nanostructured chemical into such a thermosetting resin is accomplished by dissolving or mixing the nanostructured chemical in a chemical crosslinker without the use of a solvent. However, all types and methods of mixing are effective including melt mixing, dry mixing, solution mixing, reactive and non-reactive mixing. The terms thermosetting resin and “chemical crosslinking” are used because entanglement of chains or entanglement between nanostructured chemicals and polymer chains behaves as physical crosslinks similar to traditional chemical crosslinks in behavior. This is because

Thermosetting resins with silanes R = POSS nanostructured chemicals with olefins (vinyl, allyl, cyclopentene, cyclohexene, norborene and higher carbon groups and higher carbon groups) are reacted with silane to produce the desired thermal, mechanical, electrical A thermosetting resin exhibiting mechanical and optical properties. Various hydride-containing silanes, silicones, and silsesquioxanes can be used to cure these systems by hydrosilylation (see Richtenhan et al., US Pat. No. 5,939,576). Particularly useful are trisilane and cyclic silane (FIG. 2). This is because these promote the solubilization of the vinyl resin. Also useful are organosilanes and siloxanes (not shown in FIG. 2). The hydrosilylation reaction process involves the oxidative addition of Si-H bonds across the carbon-carbon double bond and does not produce byproducts (FIG. 3). This reaction is catalyzed by all known hydrosilylation catalysts and by free radical initiators.

Sulfur thermosetting resin R = POSS nanostructured chemicals with olefinic groups react with sulfur and thiols to show outstanding thermal, mechanical, electrical and optical properties. These systems can be cured by vulcanization and thiolation methods using various sulfur-containing cure accelerators and solubilizers (see Lichtenhan et al., US Pat. No. 5,939,576). Particularly useful are disulfides and cyclic sulfur (FIG. 4). This is because these promote the solubilization of the vinyl resin. Part or all of the sulfur may be replaced by a sulfur donor such as thiuram disulfide. The accelerator determines the rate of vulcanization, but the ratio of accelerator to sulfur affects the efficiency of the cure and also the thermal stability of the resulting polymer. In addition, a promoter to sulfur ratio of typically 1: 5 is preferred, which gives a network of about 20 sulfur atoms for each intercalation chemical bridge. The reaction process involves the oxidative addition of S—H or S—S bonds across the carbon-carbon double bond and does not produce by-products (FIG. 5). This reaction is catalyzed by all known free radicals, UV and thermal initiators. Particularly useful is the activation of the curing process with zinc oxide and stearic acid, which is “accelerated” by the addition of a small amount of complex sulfur-based chemicals, typically sulfenamide. This not only accelerates the process but also affects the properties of the resin, such as its aging resistance. Although it is not possible to list all chemicals used as accelerators, some of the major groups used include thiazole, sulfenamide, and guanidine.

Thermosetting resin with phosphine R = POSS nanostructured chemicals with olefinic groups react with phosphine and exhibit significant thermal, mechanical, electrical and optical properties. Various hydride-containing phosphines and phosphates can be used to cure these systems by phosphorylation methods (see Richtenhan et al., US Pat. No. 5,939,576). Particularly useful are bis and trisphosphines and oligomeric phosphines (FIG. 6). This is because they promote vinyl-based solubilization. The reaction process involves the oxidative addition of P—H bonds across the carbon-carbon double bond and does not produce byproducts (FIG. 7). This reaction is catalyzed by all known free radical initiators and UV sources.

Olefin Thermosetting Resin R = POSS nanostructured chemicals with olefinic groups react with ene and exhibit significant thermal, mechanical, electrical and optical properties. These systems can be cured by 2 + 2 and 4 + 2 addition methods using hydride-containing enes including acetylene (also commonly known as Diels Alder). Particularly useful are linear and cyclic dienes (Figure 8). This is because they promote vinyl-based solubilization. The reaction process involves the addition of a cc double bond across the carbon-carbon double bond and does not produce a byproduct (FIG. 9). This reaction is catalyzed by all known free radical initiators and UV radiation sources.

Variations on Thermosetting Resins Variations on the listed curing methods and POSS nanostructured chemicals with olefins can be used. For example, partial derivatives of the olefinic group contained in the structure shown in FIG. 1 can be obtained by oxidation and substitution methods described by Richtenhan et al. In US Pat. Nos. 5,942,638 and 6,100,417. As well as the Heck method described by Laline et al. Derivatization of one or more vinyl groups in FIG. 1 may be desirable to increase adhesion, solubility in base or acid conditions, or to increase or decrease hydrophobicity and biochemical compatibility. The vinyl-based epoxidation in FIG. 1 is believed to be particularly useful for improving adhesion.

  Incorporation of POSS silanols and other reactive or non-reactive POSS systems would be useful as reinforcements for olefin polymers including bismaleimide and olefin-terminated polyimides. Also, the physical properties of non-olefin containing polymers such as polyimides, epoxies, urethanes can be desirably enhanced by the incorporation of POSS silanols and other POSS systems that can interact with one or more polymer chains.

Silanol Epoxy and Cyanate Ester Thermoset Resin Silanol POSS nanostructured chemicals can interact through hydrogen bonding of epoxy and cyanate ester groups and polar silanols with oxygen and nitrogen groups in the epoxy and cyanate ester polymers ( FIG. 10). Depending on the chemical structure of the hardener and nanoscale components and the curing conditions, mechanical properties ranging from extreme flexibility to high strength and hardness, as well as adhesive strength, chemical resistance, heat resistance and electrical resistance Such physical characteristics can be changed. Various chemical compositions and cure rates allow the user to process over a wide temperature range and control the degree of crosslinking.

  A considerable amount of research has been reported in the literature regarding the nature of the reaction between epoxides and amines. The cure rate of the epoxy can be accelerated by many factors, such as the addition of hydroxyl groups, alcohols and Lewis acids that occur during cure. Of these, the catalytic effect of alcohol is widely recognized. The catalytic efficiency of alcohol can be approximately proportional to its acidity. This is because the acid or electrophilic species significantly accelerates the addition of most nucleophiles by the reversible formation of the more reactive epoxide conjugate acid. A similar reaction mechanism has been proposed for Lewis acids. Our particular interest is the influence of silanol groups on the epoxy cure rate. A synergistic effect between silanol and Lewis acid (aluminum complex) has also been confirmed.

  Due to the nanoscale size, acidic POSS silanols promote further epoxy-amine crosslinking in the post-vitrification stage governed by diffusion control mechanisms. This is in the production of fiber reinforced composites using a resin transfer molding process, where it is required to maintain a low viscosity for some time to remove pores and produce a high Tg material at a low post cure temperature. It can be used advantageously. Nanoscale sized POSS is also useful for controlling the volume of reactive groups that enhance the tendency of epoxy-amine secondary hydrogen atoms to react. This ultimately makes the network structure formed more complete.

  A similar association mechanism works in the cyanate ester system. These resins are crosslinked by cyclization trimerization of OCN groups. In the presence of silanol POSS or related POSS systems (eg amines, siloxide anions, etc.), POSS increases the volume of reactive groups and subsequently increases the tendency to react more completely. Although silanol groups may add across the CN triple bond of the cyanate ester group, this secondary cure mechanism requires high temperatures to complete.

  A similar association mechanism works in polyimide systems. These resins are strongly hydrogen bonded and crosslink via the formation of polyamic acid intermediates where POSS can associate via hydrogen bonding. Subsequently, the polyamic acid is converted to a cyclic imide by heating and loss of water. In the presence of silanol POSS or related POSS systems (eg, amines, siloxide anions, etc.), POSS increases the volume of amic acid reactive groups and increases the rate of water loss due to silanol acidity, and more Increases the tendency to react completely and reduces the need for high temperature curing.

  A similar association mechanism works in the bismaleimide system. These resins are cross-linked by reaction of diallyl bisphenol A and maleimide to form a cyclic cross-link. POSS can strongly hydrogen bond with diallyl bisphenol A, increasing the volume of reactive groups and subsequently increasing the tendency to react more completely, reducing the need for high temperature curing. A similar mechanism can be used for acetylene-terminated polyimides by association with POSS imide groups.

  Similar association mechanisms work in the phenol, resorcinol, and novolak systems. These resins are cross-linked by the reaction of phenol and form a methylene cross-linked network structure by disappearance of water. POSS can strongly hydrogen bond with phenol, increasing the volume of reactive groups and subsequently increasing the tendency to react more completely, reducing the need for high temperature curing.

  A similar association mechanism works in polyurethane systems. These resins crosslink by condensation and addition reaction of alcohol or amine with isocyanate to form urethane crosslinks. POSS can strongly hydrogen bond with alcohols and isocyanates, increasing the volume of reactive groups and subsequently increasing the tendency to react more completely, reducing the need for high temperature curing.

Definition of Formula Expressions for Nanostructures To understand the chemical composition of the present invention, the chemical formula representations of polyhedral oligomeric silsesquioxane (POSS) and polyhedral oligomeric silicate (POS) nanostructures are as follows: Definitions are made.

Polysilsesquioxane is a material represented by the formula [RSiO _1.5 ] _x . Where x represents the molarity of polymerization, R = is an organic substituent (H, siloxy, cyclic or linear aliphatic or aromatic group, and further a reactive group such as alcohol, ester, amine, ketone, Which may contain olefins, ethers or halides, or may contain fluorinated groups). The polysilsesquioxane may be either homoleptic or heteroleptic. A homoleptic system contains only one R group, whereas a heteroleptic system contains two or more R groups.

  POSS and POS nanostructure compositions are represented by the following formula:

For homoleptic compositions _{[(RSiO 1.5) n] Σ} #
In the case of a heteroleptic composition [(RSiO _1.5 ) _n (R′SiO _1.5 ) _m ] _{Σ #} (where R ≠ R ′)
For functionalized heteroleptic compositions [(RSiO _1.5 ) _n (RXSiO _1.0 ) _m ] _{Σ #} (wherein the R groups may be the same or not)
In all of the above, R is the same as defined above, and X is OH, Cl, Br, I, alkoxide (OR), acetate (OOCR), peroxide (OOR), amine (NR ₂ ), isocyanate ( NCO), and R include, but are not limited to: The symbols m and n indicate the stoichiometry of the composition. The symbol Σ indicates that the composition forms a nanostructure, and the symbol # indicates the number of silicon atoms contained within the nanostructure. The value of # is usually the sum of m + n, where n is typically in the range 1 to 24 and m is typically in the range 1 to 12. Note that Σ # should not be confused with a multiplier for determining stoichiometry. This merely describes the overall nanostructure characteristics of the system (red cage size aka cage size).

Detailed Description of the Invention The present invention teaches the use of nanostructured chemicals as structural units for the reinforcement of polymer coils, domains, chains, and segments at the molecular level for thermosetting resins.

  The keys that allow nanostructured chemicals to function as molecular level reinforcing agents and alloying agents are (1) their unique size relative to the polymer chain dimensions, and (2) nanostrengthening of polymer chains Their ability to adapt to polymer systems, so as to overcome incompatibility and repulsion that promotes repulsion. That is, nanostructured chemicals can be designed to exhibit preferential affinity / compatibility with certain polymer microstructures due to changes in R groups on each nanostructure. At the same time, nanostructured chemicals can be designed to be incompatible with other microstructures within the same polymer, thus allowing selective reinforcement of a particular polymer microstructure. Thus, factors that lead to selective nano-reinforcement include specific nano-sizes of nano-structured chemicals, nano-size distributions, and compatibility and imbalance between nano-structured chemicals and polymer systems.

  Nanostructured chemicals, such as the monoscope-sized POSS structure shown in FIG. 1, are available in both solids and oils. Both forms dissolve in the solvent or core reagent, thereby solving the long-term dispersion problems associated with conventional particulate fillers or the mixing complexity associated with interpenetrating networks. In addition, since POSS nanocages dissolve in plastics at the molecular level, solvation / mixing forces (ie, free energy) cause coalescence and coalescence of POSS as occurs with traditional and other organic functionalized fillers. Enough to prevent. Aggregation of particulate filler has been a problem that has traditionally plagued compounders and molders.

  A relative comparison between POSS cage size and filler diameter / length scale relative to polymer dimensions is as follows. Amorphous segment 0.5-5 nm, octacyclohexyl POSS 1.5 nm, random polymer coil 5-10 nm, fine particle silica 9-80 nm, crystalline lamella 1.0-9,000 nm, filler / organic clay 2-100,000 nm. The size of POSS is approximately equal to the size of most polymers, so POSS can effectively change the behavior of polymer chains at the molecular level.

  The ability of POSS to control chain movement is particularly evident when POSS is incorporated into a polymer chain or network. US Pat. No. 5,412,053 to Richtenhan et al., US Pat. No. 5,484,867 to Richtenhan et al., US Pat. No. 5,589,562 to Richtenhan et al. And US Pat. No. 5,047,492 to Weidner. checking ... All of which are expressly incorporated herein by reference. When POSS nanostructures are covalently attached to polymer chains, they function to prevent chain movement and time-dependent properties such as Tg, HDT, creep and residual strain (which are high modulus, hardness, and Greatly correlates with wear resistance). Thus, the present invention shows that similar property improvements can be achieved by incorporating nanostructured chemicals into thermosetting resins. This greatly simplifies the prior art process.

  In addition, POSS nanostructured chemicals have a spherical shape like molecular spheres (according to single crystal X-ray diffraction studies) and they dissolve, so they are also effective in reducing the viscosity of polymer systems. This benefit is similar to that produced by incorporating plasticizers into the polymer, with the added benefit of reinforcing individual polymer chains due to the nanoscale nature of the chemical. Thus, while ease of processing and reinforcing effects are obtained through the use of nanostructured chemicals (eg POSS, POS), the prior art uses both processing aids and fillers or mixtures of polymer chains that are not well defined. Would have required. Further benefits can be realized through the use of monodisperse cage sizes (ie, polydispersity = 1) nanostructured chemicals or with polydisperse cage sizes. Such control over compatibility, dispersibility, and size is unprecedented for all conventional fillers, plasticizers, and interpenetrating network technologies.

Examples General Process Variables Applicable to All Processes As is common to chemical processes, there are a number of variables that can be used to control the purity, selectivity, speed and mechanism of any process. Variables affecting the process for incorporation of nanostructured chemicals (eg POSS / POS etc.) into plastics include the size, polydispersity and composition of the nanostructured chemicals. Similarly, the molecular weight, polydispersity and composition of the polymer system must be compatible with the properties of the nanostructured chemical. Finally, the speed, thermodynamics, and processing aids used during the mixing process, as well as the accelerators and curing aids used during the cross-linking process, are also provided by the incorporation of nanostructured chemicals into the polymer. It is a means of work that can affect the level and degree of improvement. Blending processes such as melt blending, dry blending, and solution blending are all effective in mixing and alloying nanostructured chemicals in plastics.

Another method: solvent assisted formulation. POSS may be added to a container containing the desired polymer, prepolymer or monomer and dissolved in a sufficient amount of organic solvent (eg, hexane, toluene, dichloromethane, etc.) or fluorinated solvent to form one homogeneous phase. . The mixture is then stirred at a sufficient temperature under strong shear to ensure proper mixing for 30 minutes and then the volatile solvent is removed under vacuum or using a similar type of process including distillation. to recover. A supercritical fluid such as CO ₂ can also be used in place of the combustible hydrocarbon solvent. The resulting formulation can then be used directly or for subsequent processing.

Example 1 Silane Cured Vinyl POSS Resin Example 1a
A sample of 70 g of vinyl POSS cage / resin mixture was stirred in 30 g of phenyltrisdimethylsiloxysilane. The mixture was heated to 60 ° C. to promote dissolution and then cured to room temperature. Next, 3 ppm of hydrosilylation catalyst was added to the mixture and stirred. The resin was then cast and allowed to react for 8 hours at room temperature, followed by heating at 60 ° C. for 4 hours and 120 ° C. for 2 hours. The optically transparent resin plate was removed and found to have excellent thermal and mechanical properties.

Example 1b-Silane Curing of Vinyl POSS and Epoxy POSS Resin / Cage Mixture A procedure similar to 1a was performed with a resin consisting of 85% vinyl POSS and 5% epoxy POSS. This was cured like 1a and was found to have nearly identical mechanical and thermal properties and high adhesion to polar surfaces including wood and composite fibers. (Note that vinyl and epoxy in the range of 0.1 to 99.9% were found to be acceptable). A further desirable feature of this resin is its optical transparency.

Example 1c-Silane curing of vinyl POSS and epoxy POSS resin / cage mixture A procedure similar to 1a was performed using a resin consisting of 80% vinyl POSS and 20% phenyl POSS. This was cured in the same manner as 1a and was found to have high fire resistance. It has been found that vinyl and phenyl in the relative range of 0.1 to 99.9% are acceptable. The optical clarity of this formulation has also been found to be a desirable property.

A ternary mixture of vinyl, phenyl and epoxy has also been found to be preferred. For example, the following ranges of vinyl POSS and phenyl POSS systems have proven useful.

Synthesis of PM1285-0510 vinyl POSS derivative:
ViSi (OMe) ₃ (184.72 g, 1.246 mol), PhSi (OMe) ₃ (82.37 g, 0.415 mol) and EpCyEtSi (OMe) ₃ (102.19 g, 0.415 mol) were mechanically mixed. Dissolved in MEK (1.5 L) and methanol (205 ml) in a 3 L three neck round bottom flask equipped with a stirrer and reflux condenser. To this reaction mixture, KOH [0.6 g, dissolved in water (149.5 mL)] was slowly added with stirring. The reaction mixture was heated to reflux and continued for 30 hours. After the reaction, HCl was added and stirred for 30 minutes. Next, 1.5 kg of ice / water and 400 mL of hexane were added and stirred for 30 minutes. The hexane / MEK layer was separated and the solvent was removed with a rotary evaporator to obtain a solid PM1285 derivative.

Example 2-Sulfur Curing Vinyl POSS cage / resin mixture (5.01 g), sulfur (0.0516 g), Captax (0.025 g), butyl zimate (0.0255 g) and methyl tuads (0.0254 g) at room temperature Mixed. The mixture was then cured at 110 ° C. for 24 hours to produce an optically clear resin plate that was found to have thermal and mechanical properties similar to those of epoxy resins.

Example 3 -Ene Curing A sample of 50 g vinyl POSS cage / resin mixture was thoroughly mixed with cumene peroxide and the mixture was heated to 100 ° C. to promote crosslinking. It was found that the optically transparent resin plate has excellent thermal characteristics. It has been found that the ability to adjust the thermal and mechanical properties of the resin produced by the ene process is possible by adding cyclopentadiene, cyclopentadiene resin, hexadiene, norbornadiene as a coene monomer reagent.

Example 4-Epoxidation of vinyl POSS cage / resin mixture A sample of 50 g of vinyl POSS cage / resin mixture was prepared from peracetic acid (200 ml), chloroform (500 ml), sodium bicarbonate (62.1 g) and sodium acetate (1.1 g). ) Was stirred and refluxed. After 2 hours, the reaction was stopped by cooling. Water (700 ml) was added at room temperature, the mixture was stirred, filtered and phase separated into an aqueous layer and an organic layer. The organic layer was separated and treated with methanol (100 ml) to give a white solid of the epoxidation product. MCPBA (metachloroperbenzoic acid) is also an acceptable oxidant that can replace peracetic acid.

Example 5a-POSS Silanol and Epoxy Curing Two conventional epoxy monomers and a conventional amine curing agent were used to demonstrate the effectiveness of the method. Diglycidyl ether of bisphenol A, DGEBA (D.E.R.w 332, Dow chemical, epoxide [E] equivalent: 173), and tetraglycidyl diaminodiphenylmethane, TGDDM (Aldrich Chemicals, [E] equivalent: 105.6). Mix with stirring, then 2-methyl-1,5-pentadiamine (Dytec A, DuPont Chemicals, hydrogen [H] equivalent: 29) or diamine-terminated polypropylene oxide (Jeffamine new D230, Huntsman Chemicals, [H] equivalent: 57 .5) was added. The ratio of epoxy (E) to amine (H) used was stoichiometric, and [E] / [H] was 1/41. To this resin mixture was added phenyltrisilanol POSS (POSS-triol) in the range of 0.1 to 1 weight percent. The resin was then heated and stirred at 50 ° C. for 30 minutes and then degassed in vacuo for 10 minutes at room temperature. The resin was poured into molds and cured for 12 hours in a mechanical convection air oven set at a specific temperature. The composition, thermal mechanical, and processing parameters are shown below.

Example 5b-POSS Epoxy Curing with Anhydride The procedure of 5a can also be applied to conventional epoxy and anhydride curing systems. For example, 3 parts of epoxide was compounded using a 45:55 weight ratio of A part POSS epoxide and B part anhydride. To this mixture was added 3 wt% imidazole catalyst and the system was thoroughly mixed at room temperature. The resin was suitable for molding or pouring. After curing at 70 ° C. for 120 minutes, the molded part was cured to room temperature and then removed from the mold. The POSS epoxy had the following desirable properties: Density 1.1-1.2 g / ml, glass transition 110-120 ° C., viscosity (after mixing) -10 poise, shelf life 12 months at 24 ° C., tensile modulus 2.2 Gpa.

Example 6-POSS silanol and polyimide cure The effectiveness of this method was demonstrated using commercially available polyamic acid (Dupont) used to form Kapton (R) films. POSS silanol was dissolved in a solution of polyamic acid in NMP solvent. The range of POSS dissolution in this mixture is 0.1 to 60 wt%, with a preferred range of 5 to 15 wt%. The solution of poly (amic acid) and POSS® in NMP is then cast into a film or coating, followed by imidization at 100 ° C. for 2 hours, then 200 ° C. for 2 hours, and 300 ° C. for 1 hour can do. Incorporation of POSS has excellent optical properties, high modulus of elasticity (E ′) at high temperatures, high toughness (elongation × tensile), and protection of silica glass on the film surface upon exposure to oxygen plasma or other oxidizing agents. Provides very improved oxidation resistance due to formation.

Example 7-POSS Silanol and Bismaleimide (BMI) Curing The method was demonstrated using a commercially available BMI resin. POSS silanol was added to a stoichiometric formulation of BMPM / DABPA (BMPM = bismaleimide monomer / polymer and DABPA = diallyl bisphenol A) manufactured by Cytec with product code 5250-4. The range of POSS silanol may be 0.1 wt% to 50 wt%, with a preferred range of 1 to 10 wt%. DABPA was first heated to 100 ° C. and then POSS silanol was dissolved prior to the addition of BMPA. All mixtures of BMI POSS silanol are optically clear, indicating complete dispersion of POSS silanol. In addition, the other modification about BMPA, for example, the dimethyl ether modification DABPA (me-DABPA) which follows the same procedure, can be used. The resulting mixture was then cured by heating at 177 ° C. for 1 hour, 200 ° C. for 1 hour, and 250 ° C. for 6 hours. The following desirable properties of the formulation were observed. Eliminating the need for a 300 ° C. curing step, viscosity at 100 ° C. = 3 cps, shelf life = 12 months, thermal strain = 689 ° F., flexural strength at 23 ° C. = 15,000 psi, elongation at 23 ° C. = 4 ~ 5%, modulus at 23 ° C. = 5.5 × 10 ⁵ psi (bending), bending strength at 275 ° F. = 9000 psi, elongation at 275 ° F. = 7-8% at 275 ° F. Elastic modulus = 5.5 × 10 ⁵ psi (bending).

Dynamic mechanical analysis of 0.8% reinforced POSS silanol BMI resin relative to the BMI control shows a 60 ° C. increase in glass transition temperature and retention of elastic modulus (E ′) at elevated temperatures relative to the BMI control. Furthermore, the presence of POSS does not affect the dynamics of the initial “cold” (177 ° C.) cycle. As a result, the workability of the system is maintained. Note that a TMI of 350 ° C. can be achieved with BMI alone, but this also requires a post cure at 300 ° C. for an additional 2 hours. In contrast, POSS BMI uses a low temperature, high speed, and simplified cure cycle (1 hour at 177 ° C., 2 hours at 200 ° C., and 6 hours at 250 ° C.) to give a T _g of 365 ° C. . In addition, the fact that the elastic modulus of POSS-BMI does not drop so much at 400 ° C. provides an important possibility for high temperature composites.

  To evaluate the composite properties of POSS BMI, a 4 ply 6 "x 6" T650-35 carbon fabric composite panel is produced using a commercial grade Cytec 5250-4 resin reinforced with 5 weight percent POSS PMI. did. The interfacial adhesion of POSS-BMI to the BMI control was evaluated by performing a short beam shear test. Five samples were tested and the average shear strength was found to be 59.14 ± 2.00 with 5% POSS BMI versus 58.44 MPA ± 2.68 with the 5250-4BMI control.

Example 8-POSS Silanol and Telechelic Polyimide Curing Synthesis of telechelic polyimide resin (PMR) involves dissolving dialkyl ester, diamine and monoalkyl ester (end cap agent) in low boiling alkyl alcohol (ie methanol). To this mixture is added POSS silanol at various weight percentages of 0.1 to 50 wt%, with a preferred charge range of 1 to 15 wt%. Since POSS silanol and PMR are soluble in alcohol, the resulting viscous solution can be used to impregnate fibers or fabrics to obtain a prepreg. The prepreg comprises a homogeneous mixture of PMR and POSS reactants upon removal of the solvent. When heated to a temperature between 150 ° C. and 200 ° C., PMR undergoes an in situ condensation reaction to produce an end-capped imide oligomer. Depending on the reaction conditions (temperature / pressure) of the endcap agent used, the final cure (thermoset) is usually from 315 ° C. (600 ° F .: Nasic ester, NE) to 371 ° C. (700 ° F .: phenylethynylphthalic acid methyl ester , PEPE). The value of POSS of this system was confirmed using a commercially available PMR resin. To HFPE-II-52 PMR resin (NASA second generation resin), POSS silanols such as trisilanol phenyl POSS and trisilanol ethyl POSS were added.

When cured, an optically clear resin was obtained. The modulus plot for the PMR control and POSS PMR reveals an increase in retention of modulus at elevated temperatures for the POSS PMR system.

To demonstrate this desirable property of POSS PMR resin versus PMR resin in a composite, an eight-ply (90/0) T650-35 carbon fabric composite panel was fabricated using HFPE-II-52 PMR and POSS HFPE-II PMR. Made using. Composite panels containing 7 wt% and 15 wt% ethyltriol and phenyltriol in HFPE-II-52 CFC show superior processability compared to non-POSS containing resins. In addition, the density of POSS triol is less than HFPE PMR, which allows the POSS-containing composite to have a low density, which helps to obtain a “light” composite structure.

In addition, the composite samples were subjected to thermal aging and their mechanical properties were evaluated using a three point bend test. Tests at 315 ° C. (600 ° F.) show that composites made with 15 wt% addition of trisilanol ethyl POSS have an average 10% increase in flexural strength, and composites made with 15 wt% addition of trisilanol phenyl POSS. Showed a 15% improvement in bending strength.

  Although the invention has been described above with reference to specific embodiments, changes and modifications will no doubt be apparent to those skilled in the art. Accordingly, the claims are intended to be construed to cover all such changes and modifications as long as they are within the true spirit and scope of this invention.

Some typical examples of polyvinyl-containing nanostructured chemicals (including fewer vinyl functional groups) are shown. Several different silanes useful for forming thermosetting resins by hydrosilylation reactions are shown. Figure 3 shows a hydrosilylation process. Several different sulfur curing agents useful for forming thermosetting resins are shown. 1 illustrates one aspect of a sulfur curing process. Several different phosphorylated curing agents are shown. The phosphorylation process is shown. Several different ene curing agents are shown. 2 shows a 2 + 2-ene curing process. Figure 2 shows the formation of a crosslinked network by association of silanols with reactive epoxy groups. Similar mechanism for imide and cyanate esters, and urethane polymers.

Claims (23)

A method of blending a nanostructured chemical into a thermosetting polymer comprising the step of mixing the nanostructured chemical with an additive selected from the group consisting of a resin and a curing aid, accelerator and catalyst. The method of claim 1, wherein a plurality of nanostructured chemicals are incorporated into the polymer. The method of claim 1, wherein the thermosetting mixture is in a physical state selected from the group consisting of oil, amorphous, semi-crystalline, crystalline, elastomeric, rubber and cross-linked material. The method of claim 1, wherein the polymer comprises a chemical sequence and an associated polymer microstructure. The method of claim 1, wherein the polymer is a polymer coil, a polymer domain, a polymer chain, a polymer segment, or a mixture thereof. The method of claim 1, wherein the nanostructured chemicals reinforce the thermosetting resin at the molecular level. The method of claim 1 wherein the formulation is non-reactive. The method of claim 1 wherein the formulation is reactive. The method of claim 1, wherein the physical properties of the thermosetting polymer are improved as a result of incorporating the nanostructured chemical into the polymer. The physical properties include adhesion to polymer surface, adhesion to composite surface, adhesion to metal surface, water repellency, density, low dielectric constant, thermal conductivity, glass transition, viscosity, melt transition, storage modulus, 10. The method of claim 9, comprising an element selected from the group consisting of relaxation, stress transfer, rub resistance, fire resistance, biocompatibility, gas permeability, and porosity. The method of claim 1, wherein a silane curing agent is used. The method according to claim 1, wherein a sulfur curing agent is used. The method according to claim 1, wherein a phosphorus curing agent is used. The method of claim 1, wherein an ene curing agent is used. The method of claim 1, wherein the nanostructured chemical functions as a plasticizer. The method of claim 1, wherein the nanostructured chemical functions as a filler. The method of claim 1, wherein the nanostructured chemical functions as both a plasticizer and a filler. The method of claim 1, wherein the nanostructured chemical is selectively incorporated into the polymer so that the nanostructured chemical is incorporated into a predetermined region within the polymer. A method of controlling the molecular motion of a polymer comprising incorporating a nanostructured chemical into the polymer. 19. The method of claim 18, wherein time dependent properties are improved as a result of incorporating the nanostructured chemical into the polymer. 21. The method of claim 20, wherein the time dependent property is selected from the group consisting of Tg, HDT, elastic modulus, creep, residual strain, transmittance, corrosion resistance, and friction resistance. A method of reinforcing selected regions of a polymer comprising formulating a nanostructured chemical having chemical properties compatible with the selected region of the polymer. The method of claim 1 wherein an epoxy modified vinyl component is used.

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